I take this vitamin everyday. I take it in the morning and in the evening. I have seen such a change in my fingernails and hair. My fingernails are so strong and grow so fast. If I forget to take biotin or run out and do not take it for a few days, I can really see a difference. I love that my nails are strong and I always get compliments when I go to get a manicure. My hair also grows much faster and looks healthier and thicker. Natures Bounty is a quality brand and I love that they are so reasonably priced. I take these vitamins with a full glass of water and have never had any side effects or negative results. I try to stock up when they are on sale at the local drug store and can usually find a coupon to match with the sale, making this brand the best priced on the market. The quality is fantastic and Natures Bounty has become my favorite brand for any type of vitamin that I am looking for. I would highly recommend this product!